You are going about the process all wrong. This isn't a negotiation. You need to write up the specs of this job how you want it done and give that to several contractors to elicit bids. That way they are all bidding on the same thing. You've halfway gotten into bed with this guy and haven't even established the parameters of the job. You're assuming one first of all that he is even capable of doing the job correctly. Have you verified his license? His insurance? His references? Did you even talk to more than one contractor? How did you even get a price of 3K when you haven't even clarified the work to be done? (BTW 3K is awfully low for the work you are describing. As in too good to be true.)

Only AFTER you have developed the list of projects and processes can you even begin to talk to contractors or get meaningful prices.

Thank you, hollysprings. You make good sense. I've been going about this wrong.

I got two other bids- one was double the price, the other was for $2500 but the contractor isn't licensed with the ROC. I didn't have a list of specifics to give them, because I didn't know what was needed (I don't know much about construction- my husband did).

It's not easy getting contractors willing to work on manufactured homes. Most of the ones that do are only handymen, not general contractors licensed by the ROC.

The contractor I chose specializes in bathroom remodeling. He's licensed in good standing with the ROC, is insured, and has no complaints filed against him that I've been able to find (I've looked).

Since posting this question I learned that a window or vent, as well as waterproofing the walls around the tub/shower are both required by code.

OK, I talked to the contractor. He said they always waterseal the hardiebacker board around the bathtub/shower, it's included in the bid at no extra charge.

They will waterseal the window and wrap it in tile, so it can stay. It's already tempered glass, so it's up to code.

They will use 3/4" plywood in the floor under the bathtub, toilet and vanity. I'm OK with that. He's willing to do everything I want.

He wants a check for 50% down when they come to start work. Is that customary?

Holly had great points. Take a step back and slow down. Now that you know more what should be involved with the project - write it up, and ask him to re-quote the job, and add in any specifics you have not included and have him list out all the products and process he will go through. Ask a few others to re-bid. DO NOT ever hire an unlicensed contractor. Except maybe to hang a picture. You are just asking for problems. If you don't do this, you will second guess him and be worrying about everything he does and he may very well be taking short cuts because it's cheaper and not spec'd. But even if it's spec'd, believe you me, it does not mean he will follow the spec. You have to watch everything. And yes, that price sounds low. Best of luck. Keep us informed.

That does sound a little low, but hard to judge from the posted info. We were quoted about that much to replace our tub, but that meant ripping out and replacing all the surrounding drywall because it was attached to studs as well as making and patching an access site for the plumbing on the other side of the bathroom wall. I had planned on DIY for the rest of the work, but since the GC was going to be there anyway, I asked for a whole room quote including tiled floor and new paint. It was double just the tub, but also done in just a few weeks vs probably a year for DIY with my schedule. We supplied the tile, vanity, toilet, mirror, medicine cabinet, and accessories. He supplied the tub, surround, and all needed materials.

Cement board over vinyl? Run, Forrest, run!

Yes, that is indicative of low standards as the norm. Also what's odd is you mention that you "do not like his tile". What contractor stocks tile anyway? perhaps he kept some extras from a previous job? That's just weird. Yes, select your own tile and talk to reputable tile guys and learn their process. I bet you won't be going with this guy. good luck.

If you are having problems now, it would be best to get things in writing - and then READ the fine print. Our kitchen contractor charged us quite a bit on anything that was not written, little incidentals, like actually installing the refrigerator, a wall measurement that was off... Be careful. If you are uncertain now, it might be best to shop around. I've learned the hard way that the only way to hire a contractor is by checking his references and making sure you trust those references. Check like with like: If it's a bathroom, look at all the bathrooms he's done.